How do you tell if 440 is magnum block?

Answer 1

there is no reference to a magnum block in the automotive engine rebuilders association cylinder head and block identification book. the magnum as far as I know, is determined by the cylinder head castings, port volume sizes and valve sizes. the crankshaft should be forged steel with a wide parting line about a quarter inch wide, and should have a wider beam on the connecting rods. these are called "six pack rods" I have no dimensions to give you but if you put them up against a stock set of rods, there is a noticeable difference. another thing, if you have a Maltese cross on the flat machined pad near the distributor, i believe that means that the main bearing bores or lifter bores are .010 oversize, i cant remember which, its been awhile. A little checking out will give you the answer. I had a few interceptors from state police cars that had this marking and were high performance.